1 files changed, 79 insertions, 0 deletions
diff --git a/lib/gitlab/metrics/transaction.rb b/lib/gitlab/metrics/transaction.rb
new file mode 100644
index 00000000000..68b86de0655
--- /dev/null
+++ b/lib/gitlab/metrics/transaction.rb
@@ -0,0 +1,79 @@
+module Gitlab
+  module Metrics
+    # Class for storing metrics information of a single transaction.
+    class Transaction
+      THREAD_KEY = :_gitlab_metrics_transaction
+
+      attr_reader :uuid, :tags
+
+      def self.current
+        Thread.current[THREAD_KEY]
+      end
+
+      def initialize
+        @metrics = []
+        @uuid    = SecureRandom.uuid
+
+        @started_at  = nil
+        @finished_at = nil
+
+        @values = Hash.new(0)
+        @tags   = {}
+      end
+
+      def duration
+        @finished_at ? (@finished_at - @started_at) * 1000.0 : 0.0
+      end
+
+      def run
+        Thread.current[THREAD_KEY] = self
+
+        @started_at = Time.now
+
+        yield
+      ensure
+        @finished_at = Time.now
+
+        Thread.current[THREAD_KEY] = nil
+      end
+
+      def add_metric(series, values, tags = {})
+        tags   = tags.merge(transaction_id: @uuid)
+        prefix = sidekiq? ? 'sidekiq_' : 'rails_'
+
+        @metrics << Metric.new("#{prefix}#{series}", values, tags)
+      end
+
+      def increment(name, value)
+        @values[name] += value
+      end
+
+      def add_tag(key, value)
+        @tags[key] = value
+      end
+
+      def finish
+        track_self
+        submit
+      end
+
+      def track_self
+        values = { duration: duration }
+
+        @values.each do |name, value|
+          values[name] = value
+        end
+
+        add_metric('transactions', values, @tags)
+      end
+
+      def submit
+        Metrics.submit_metrics(@metrics.map(&:to_hash))
+      end
+
+      def sidekiq?
+        Sidekiq.server?
+      end
+    end
+  end
+end